Tyranna Resources has identified high-grade surface anomalies at its Coola project in Angola, including soil assays of up to 13.18% TREO and 3.9% Nb₂O₅. The results refine drill targets ahead of a maiden program planned for the second quarter of 2027, subject to wet-season conditions.
- 13.18% peak TREO soil assay from historic sampling
- 3.9% peak Nb₂O₅ soil assay
- Rock chips returned up to 4.85% TREO and 2.85% Nb₂O₅
- Coola carbonatite ring dyke is described as drill-ready
- Maiden drilling targeted for Q2 2027 after the wet season
Coola soil sampling defines rare earths and niobium targets
The most eye-catching result from Tyranna Resources Limited (ASX:TYX) is a 13.18% TREO soil assay at the Coola Prospect in central Angola. The historic dataset, comprising about 1,084 samples, produced 185 results above 1.5% TREO, including 26 above 5%. Niobium was also prominent: 25 samples exceeded 2% Nb₂O₅, with a peak of 3.9%.
The anomalies are concentrated around an incomplete carbonatite ring dyke with a circumference of roughly 3 kilometres. Tyranna describes the structure as drill-ready, with anomalous TREO and/or Nb₂O₅ geochemistry covering much of the ring. Rock sampling provides a second surface signal, with 11 of 79 rock chips returning between 2.12% and 4.85% TREO, while 10 samples returned between 1.03% and 2.85% Nb₂O₅.
Historic drilling adds support but not a resource
Earlier auger work within the central diatreme produced eight assays between 1.04% and 1.92% TREO from holes drilled adjacent to exposed carbonatite. Reverse-circulation drilling also encountered ultramafic rock or brecciated carbonatite in seven holes, although the company has not yet reported laboratory assays from that work. Selected samples were screened with a pXRF and are due for commercial laboratory analysis during the December quarter.
The Coola results add geological substance to Tyranna’s 70% Coola earn-in, which was reported as conditional on renewal of the project tenement. Tyranna says its subsidiary may earn a 70% interest in Coola Mining LDA, the company holding the project. The wider title covers 830 square kilometres and contains four identified alkaline intrusions, two of which include mapped carbonatite phases.
Surface grades still need to survive the drill test
For investors, the important qualification is that these are chiefly historic exploration results supplied by the vendor, rather than new drilling intersections or a mineral resource. The announcement contains no resource estimate, economic study, recoveries or niobium metallurgical work. Mineralogical testwork identified bastnäsite, monazite and florencite in one hand-picked carbonatite sample grading 3.72% TREO, but Tyranna says no work has been undertaken to identify the niobium minerals.
The company’s competent person, Jonathan Smalley, said the vendor data was suitable for reporting under the JORC Code after reviewing laboratory certificates, quality-control data and sample records. He has not visited the project. That leaves the planned drilling as the decisive next step in testing whether the spectacular surface anomalies reflect continuity and thickness beneath the soil cover.
December work leads into Q2 2027 drilling
Tyranna plans to collect 500 additional soil samples across the wider Sulima West and Mt Verde prospects during the December quarter, while integrating historic data and sending selected RC, trench and exploration-pit samples for laboratory analysis. Maiden drilling at Coola is targeted for the second quarter of 2027, after Angola’s usual November-to-March wet season, although the company makes the timing subject to the season’s duration.
The project’s location near other developing critical-minerals assets gives the exploration program a clear regional reference point: Tyranna says Pensana’s Longonjo rare earths project is about 45 kilometres south of Coola, while the Niobonga niobium project is about 250 kilometres to the southwest. Whether Coola can move beyond impressive surface chemistry will depend on the quality of Tyranna’s target selection, the laboratory results still outstanding and what the first proper drill campaign finds below the ring dyke.
Bottom Line?
The surface numbers are unusually strong for an early-stage target, but Coola remains an exploration story until drilling demonstrates continuity, depth and scale.
Questions in the middle?
- Will the pending laboratory assays from RC drilling confirm the pXRF-screened results?
- Can drilling establish continuous mineralisation beneath the Coola ring dyke rather than isolated surface anomalies?
- Will the project-title extension and wet-season timing allow the maiden drilling program to begin in Q2 2027?